Ecosystem dynamics

Question 1

describe the difference between a decomposer and a detritivore

Answer 1

Decomposers break down dead matter via external digestion, whereas detritivores obtain nutrients by ingesting and digesting dead matter (i.e. external vs internal digestion)

Question 2

give an example of energy transformation in an ecosystem

Answer 2

solar energy is transformed into chemical energy via photosynthesis

Question 3

how much energy is passed on between trophic levels, and what causes the loss of energy?

Answer 3

approximately 5-20% of energy is passed on between trophic levels due to the loss of energy to the surroundings in the form of heat (metabolism + maintenance) and to decomposers/detritivores

Question 4

describe the movement of water through an ecosystem

Answer 4

when water meets cool air, it condenses and forms clouds. it falls to the ground as precipitation when the volume of water in a cloud reaches critical levels. most precipitation falls directly in the ocean, but rain that falls on land is pulled to the ocean by gravity (e.g. surface run-off, rivers, etc.).
some water soaks into the soil and percolates down until reaching a zone of saturation (which flows back to the ocean eventually or is taken up by plants).
most water taken up by plants returns to the atmosphere via transpiration.